<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button id="btn" onclick='show()'>点我</button>


    <script>
        const btn = document.getElementById('btn')
        // btn.onclick=()=>{
        //     alert(1)
        // }

        // btn.addEventListener('click',()=>{
        //     alert(1)
        // })

        function show(){
            alert(1)
        }
    </script>
</body>
</html>